Polyhedral, porous, and hollow block

ABSTRACT

A polyhedral structural block having a hollow core and perforated surfaces, which is useful in forming underwater structural foundations for revetments, breakwaters, dikes, jettiers, piers, abutments and the like, comprising six apertured, flat rectangular sides and twelve apertured, flanged rectangular sides wherein the adjacent flanges of the latter are arranged so as to form eight open triangular sides.

United States Patent 1 1 Chang 451 July 29,1975

1 1 POLYHEDRAL, POROUS, AND HOLLOW BLOCK [76] Inventor: Dall Chin Chang,K0 Ho, 85 Block,

Suhkyo-dong Mapo-Ku, Seoul, South Korea [22] Filed: May 3, 1974 [21]Appl. No.: 466,639

[30] Foreign Application Priority Data May 3, 1973 South Korea 719 [52]US. Cl 61/4; 61/4 [51] Int. Cl." E02B 3/04 [58] Field of Search 61/3, 4,5; 52/608, 609, 52/610, 6l1;249/118,l55, 156,153,163; 46/23, 24, 25

[56] References Cited UNITED STATES PATENTS 2,839,841 6/1958 Berry 46/23X 3,276,148 10/1966 Snelson 46/25 X 3,276,210 10/1966 Stitt 61/53,368,357 2/1968 Takamori.... 61/3 X 3,548,600 12/1970 Stolk et a1 61/43,665,882 5/1972 Georgier et a1. 52/608 UX 3,759,043 9/1973 Tokunaga61/4 R24,632 4/1959 Danel et a1. 61/4 FOREIGN PATENTS OR APPLICATIONS2,031,397 12/1971 Germany 52/608 Primary ExaminerDennis Taylor Attorney,Agent, or Firm.1ames C. Haight [57] ABSTRACT A polyhedral structuralblock having a hollow core and perforated surfaces, which is useful informing underwater structural foundations for revetments, breakwaters,dikes, jettiers, piers, abutments and the like, comprising sixapertured, flat rectangular sides and twelve apertured, flangedrectangular sides wherein the adjacent flanges of the latter arearranged so as to form eight open triangular sides.

5 Claims, 10 Drawing Figures PATENTEDJUL29|975 3,896,624

SHEET 1 H5. 54 Eli. 5

POLYI-IEDRAL, POROUS, AND HOLLOW BLOCK BACKGROUND OF THE INVENTION Thisinvention relates to a polyhedral, structural block having a hollow coreand perforated surfaces, which is useful in forming underwaterstructural foundations and in river and shore engineering construction.More particularly, this invention relates to a polyhedral structuralblock which will provide a stable foundation on underwater mud layersfor the construction of a breakwater, dike, seawall, quaywall, revetmentor the like.

Silt and mud layers often found at the bottom of rivers and shores areoften soft and floating, so that when solid foundation material such asrock, concrete blocks or the like is dropped into the mud layer, thevertical center portion of a structure constructed thereon will sink dueto the heavy deadload, while the inner and outer areas around theperiphery subside to a lesser extent, resulting in an unstablefoundation. At the same time, mud which is pushed out by the sinkingcenter of the foundation will accumulate at the sides of the structurebottom, so that the mud foundation itself of the sea bottom accumulatedabout the structure over a period of time will be spread out. In such astate, the wave forces generated by storms and tidal currents oftencause the structure to collapse or wash away.

Another disadvantage frequently encountered in the use of the aboveobjects is due to the small surface area and frictional resistance ofthe individual objects which do not bind to each other when dropped intoa mud layer. Thus, slippage is relatively easy and the deadload ofstructures constructed thereon results in an uneasy support. When wavesgenerated by heavy storms or tidal currents strike the upper portion ofsuch structures, the structure itself often collapses. Due to thestrength of the currents and tides in water waves and overflows, thisusually occurs and often causes a revetment. embankment, breakwater orguide structure to collapse prematurally.

It is furthermore heretofore been impossible to accurately estimate bygood engineering design the quantity and weight of rock required to bedropped into a given mud layer. Even a rough survey requires drivingpiles into the mud, but such efforts are generally unsatisfactory inyielding the desired data, and design work has been largely based oninaccurate or incomplete data obtained from past experience. During theconstruction process, the increase or decrease in the quantity of rockrequired over that calculated has been determined by the quantity ofrock being sunken into a mud layer or being washed away. Thus, anyerrors in determining this increase or decrease result in either anearly destruction of the structure or in a waste of construction funds.

Underwater structures in both fresh and salt water provide shelter formany types of aquatic and marine life. However, even these relativelysheltered populations have been threatened due to a rapid improvement offishery techniques and reckless catches. In order to preclude recklesscatches and to provide an inhabitable place to protect and breed fisheswhile still permitting sport fishing, porous blocks have recently beenutilized to serve as objects with which to damage fishing nets in aneffort to discourage fishing in a specific area.

OBJECTS OF THE INVENTION Accordingly, it is a general object of thepresent invention to provide a structural block which is useful inconstructing underwater foundations.

Another object of this invention is to provide such a structural blockwhich is three dimensionally symmetrical and therefore need not beself-righting.

A further object of this invention is to provide a hollow-corestructural block which is self-draining, thereby avoiding damage causedby filling and draining stresses.

An additional object of this invention is to provide a structural blockcapable of retaining particulate matter therein while permitting waterto flow therethrough.

Yet another object of this invention is to provide a structural blockwhich discourages heavy fishing in the sheltered area which it provides.

A still further object of this invention is to provide increasedfrictional resistance between adjacent structural elements of anunderwater foundation.

Still another object of this invention is to provide a structural blockwhich can be prefabricated from only two component parts, which can betransported for assembly at a construction site.

Other objects of the present invention will become apparent to thoseskilled in the art upon further study of the specification and appendedclaims.

SUMMARY OF THE INVENTION Briefly, the above and other objects areattained in one aspect of the present invention by providing apolyhedral structural block having a hollow core and perforated surfaceswhich is fabricated from six flat rectangular first structural members,preferably having an aperture formed through the planar surface thereof,and twelve flat rectangular second structural members, also preferablyhaving an aperture formed in the planar surface thereof, the secondmembers having a pair of flanges extending outwardly from a pair ofparallel edges thereof. The assembled block is hollow and perforated,and is assembled in such a manner that three adjacent flanges from thesecond members form triangular openings to permit the flow of watertherethrough and protruberances which can damage fishing nets andtherefore discourage heavy fishing.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, featuresand advantages of the present invention will become more fully apparentto those skilled in the art to which this invention pertains from thefollowing detailed discussion, taken in conjunction with the annexeddrawings wherein like or corresponding reference numerals refer to likeor corresponding parts in the several figures, and in which:

FIG. [is a perspective view of the assembled polyhedral, perforatedhollow block of the present invention; FIGS. 2A and 2B show aperspective view of the two rectangular members used to construct theblock, FIG. ZA showing a member with flanges and FIG. 2B showing amember without flanges;

FIG. 3 is a plan view taken along vertical section 33 of FIG. 1;

FIG. 4 is a plan view taken along horizontal section 44 of FIG. 1;

FIG. 5 is a schematic illustration, partially in crosssection, of anunderwater foundation constructed in accordance with the presentinvention;

FIG. 6 is an analogous view of a similar structure con structed of arock base on a layer of mud;

FIG. 7 schematically illustrates a section of reservoir revetment builton a foundation in accordance with this invention;

FIG. 8 is a schematic view of a fish shelter provided by blocks of thepresent inventions; and

FIG. 9 is a perspective view, partially in crosssection, schematicallyillustrating flow through the block.

DETAILED DISCUSSION The rectangular members used to form the blocks ofthis invention can be constructed of any material suitable forunderwater use, e.g., steel, concrete, bound aggregate and the like, theonly requirement being that the material have sufficient structuralstrength, a nonslippery surface, and be suitable for use under water.Preferably, either the flat rectangular members or the flangedrectangular members, or preferably both, are formed about centrallylocated apertures of a suitable size. This functions to not only reducethe weight of the block itself without a significant decrease in thestrength thereof, but also permits improved circulation of water, siltand mud into the hollow block core. By the provision of multiple facesand angles, frictional resistance between adjacent blocks is increasedand the resistance to movement of the block itself in a layer of mud isgreatly enhanced. Furthermore, the mud surrounding a pile of such blockson a sea or river bottom can enter into the inside of the inner blocks,thereby minimizing mud accumulation around the periphery and greatlyenhancing the stability of the foundation. The blocks are particularlyuseful in constructing structures such as a closing dike, sea wall ortemporary revetment for reclamation which connects the river embankmentsor shore ends, or a groin, guide wall or the like to control currents,or a low water revetment which protects an area of shore from errosion.The large volume, heavy weight, multi-holed block will provide not onlya stable foundation, but also decrease the velocity of water flowingtherethrough and retain deposits in the hollow inner core. This isespecially valu able in situations where tidal currents or river waterflow is encountered, since the hollow core will fill with particulatematerial to form a heavy block and the flow of water through the holesthereofis at a decreased velocity. Thus, the blocks can be firmly set sothat a structure constructed thereon will not be destroyed but ratherwill be safely protected. The provision of both large and small holesfurther allows fish to enter and leave the shelter which is naturallyprovided by an accumulation of such blocks.

Referring to the drawings, it can be seen that the block can beconstructed in accordance with the principles of this invention usingonly two modular members l0 and 12. Six flat rectangular first members10, preferably having an aperture 14 formed through the planar surfacesthereof. e.g., of the type shown in FIG. 2B, are preferably bevelledalong the edges I6, 16' as shown. Twelve flat rectangular second members12 also preferably having an aperture 14 formed through the planarsurfaces thereof and having a pair of flanges l8, 18' extendingoutwardly from a pair of parallel edges thereof are also employed,giving a total of eigh teen flat surfaces having holes in the center.When assembled, the flanges form eight triangular protruberances 22defining triangular holes in each block. Therefore, the preferred hollowblock has eighteen holes on eighteen faces and another eight triangularholes, each formed by the edges of three adjacent flanges, for a totalof 26 holes. The bevelled edges 16, 16' of the first and second members10 and 12, respectively, facilitate joint welding or adhesive bonding,e.g., with a polyester resin of adjacent flat surfaces at a 45 angle.Alternatively, exposed reinforcing bars or other structural equivalentscan be provided in place of the flanges.

It will be appreciated that while the presently preferred embodiment ofthis invention is constructed by assembling eight flat members and I2flanged members, the exact configuration of the polyhedral structuralblock can be modified in accordance with known principles of solidgeometry to a greater or lesser number of total members, includingmodifying the shape of the protruberances if necessary. However, as thenumber of sides of the polyhedron increases, the resistance againstsliding and rotation decreases because the block becomes more spherical,which is undesirable.

Referring to FIG. 2B, flat rectangular member 10 is shown in a preferredapertured configuration with all edges thereof bevelled at an angle of67.5 to eliminate alignment problems in assembly. Two such adjacentbevelled surfaces when fitted together form a right angle and impart a22.5 offset to the plane of each member on which they are formed,resultng in a net 45 angle between adjacent members and the formation ofa generally annular closed 360 ring when eight modular members arebrought together at sixteen such parallel bevelled edges.

Referring to FIG. 2A, the second flat rectangular members are preferablyof the same dimensions and configuration around the inner perimeter asthe first members, and two parallel outer edges thereof are similarlybevelled at an angle of 67.5". The other two parallel sides extend at anobtuse angle to the rectangular surface to form a flange whichterminates laterally in angularly faceted surfaces such that assembly ofthree such flanges by mating the faceted surfaces will form a closed,hollow triangular protruberan'ce 22. As can be seen from FIG. 3, theflanges and accordingly the plane of the triangle so formed ispreferably at a angle to the surface of each adjacent second member,whereby the axis of the triangular protruberance extends outwardly fromthe center of the polygon.

The faceted portion 20, 20' of flanges 18, 18' are formed at anoutwardly obtuse angle with respect to the flat bottom surface of thesecond members and the plane thereof is perpendicular to the center ofthe rectangle, such that six such mated surfaces of three flanges fitsmoothly together to form the solid corners of the triangle. The facetplane will preferably intersect inner surface at a 45 angle to eachintersecting edge of the inner surface and the flange segment thereofextends outwardly at an angle of 135 from the flat surface of saidmember.

The provision of both rectangular and triangular joining surfaces invarious planes is an important aspect of this invention, since thestability and structural strength of the block is greatly increasedthereby.

Referring to FIG. 1, it can be seen that the assembled block forms apolyhedron characterized by a. a first generally annular ring formedfrom a plurality of alternating first and second rectangular members,the surfaces of each member being at an acute angle to the surfaces ofabutting members and the flanges of said second members extendingradially and outwardly along the outer perimeter of said ring;

b. a second generally annular ring disposed at right angles to saidfirst ring and having an imaginary axis which intersects an imaginaryaxis of the first ring at a point inside a hollow core, said second ringbeing formed from a plurality of alternating first and second membersand having a pair of opposed first members in common with said firstring, the flanges of the second members thereof extending radially andoutwardly along the perimeter of the second ring and each flangeabutting an adjacent flange on the first ring to form an acute angletherewith; and

c. a third generally annular ring disposed at right an gles to both saidfirst and second rings and having an imaginary axis which intersects theintersecting axes of said first and second rings, said third ring beingformed from a plurality of alternating first and second members andhaving one pair of opposed first members in common with said first ringand a second pair of opposed first members in common with said secondring, the flanges of the second members thereof extending radially andoutwardly along the perimeter of the third ring and abutting adjacentflanges on the first and second rings to form acute angles thereto,whereby a protruberant triangular opening is defined by abutting flangesof the three rings protruding outwardly from said members.

In a preferred embodiment, the flat first members are bevelled alongedges 16 thereof at an acute slope, e.g., of about 675, while theflanges on the second members slope from the outer surface at an obtuseangle, e.g., about 135, preferably of about 126. Assembly is facilitatedby first forming a triangle 22 from three abutting flanges, and thencovering and welding the first flat members to the spaces provided tocomplete assembly of the polyhedral, hollow block.

Both the first and second members 10, 12 can be easily mass produced ata distant factory and cured prior to transporting the prefabricatedslabs to a construction site for assembly, e.g., using a concretepolyester joining composition to fasten the side faces together, priorto dropping the blocks into the water.

In actual operation, the blocks when dropped into the sea will sink dueto their own weight. Once the block reaches a soft mud layer 24 at thebottom, the mud enters the hollow interior through both the triangularholes formed by the flanges and the apertures in the faces of therectangular members as is illustrated in FIG. 9. Thus, the undesirablemud accumulation which occurs when using solid rock or similarmaterials, indicated as 26 in FIG. 6, does not occur. Furthermore, theweight of the blocks is increased due to the mud fill, which facilitatespassage through the mud layer to rest on a hard bottom surface 28.

Because flanges 18 and protruberant portions 22 function to increase thefrictional resistance between adjacent blocks, and because contact withmud 24 increases shear resistance, the blocks are prevented from freerotation in a soft mud layer. Since the block is geometricallysymmetrical and water permeable, it sinks vertically of its own weightand the blocks are easily dropped to the bottom at equal intervals.

When dropped into a river, the bottom blocks become gradually embeddedinto the silt and settle firmly. As silt is carried by the current andthe blocks permit the passage of water therethrough, the silt and sandaccumulation will eventually take place indownstream blocks as well,causing these blocks also the settle firmly. I

For use inconducting revetments or sea walls in land reclamation, theholes serve not only as a means of increasing the weight of the block bycollecting silt or soil therein, but further to drain water therethroughfrom changing tides or waves, thereby obviating stresses which normallyoccur during the drainage of large volumes of water from a solid object.In order to reduce the water velocity inside the block, a bundle ofbranches can be inserted to slow down the velocity and aid inaccumulating silt, which contributes to building up and protecting astable structural foundation. The protruding triangular portion 22formed by flanges 18 provides increased rotational resistance in a bedof silt or mud; portions of these protruding triangles can beaccidentally broken off without impairing the structural strength andfunctioning of the block. Portions protruding from the sea or river bedfurther act as a hook to damage fishing nets, thereby discouraging heavyfishing of the sheltered area provided.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

What is claimed is:

l. A polyhedral structural block suitable for use in constructingunderwater foundations, having a hollow core and perforated surfaces,comprising in combination:

a. a plurality of flat rectangular first members;

b. a plurality offlat rectangular second members having a pair offlanges extending outwardly at an obtuse angle from a pair of paralleledges thereof, said plurality being twice the number of flat rectangularfirst members;

0. a first generally annular ring formed from a plurality of alternatingfirst and second rectangular members, the surfaces of each member beingat an acute angle to the surfaces of abutting members and the flanges ofsaid second members extending radially and outwardly along the outerperimeter of said ring;

d. a second generally annular ring disposed at right angles to saidfirst ring and having an imaginary axis which intersects an imaginaryaxis of the first ring at a point inside said hollow core, said secondring being formed from a plurality of alternating first and secondmembers and having a pair of opposed first members in common with saidfirst ring, the flanges of the second members thereof extending radiallyand outwardly along the perimeter of the second ring and each flangeabutting an adjacent flange on the first ring to form an acute angletherewith;

e. a third generally annular ring disposed at right angles to both saidfirst and second rings and having an imaginary axis which intersects theintersecting axes of said first and second rings, said third ring beingformed from a plurality of alternating first 7 8 and second members andhaving one pair of opeach generally annular ring is formed of eight ofsaid posed first members in common with said first ring b and a second pof pp first members in 3. A structural block according to claim 2,wherein mom with Said Second ring, h flanges of the the edges of saidfirst members are bevelled at about a nd members thereof extendingradially and out- 67 o angl wardly along the perimeter of the third ringand abutting adjacent flanges on the first and Second 4. A structuralblock according to cla1m 3, wherein rings to form acute angles thereto,whereby a the flanges on said second members extend at an obtruberanttriangular opening is defined by abutting tuse angle of about 126flanges of the three rings protruding outwardly l0 5. A structural blockaccording to claim 4, whereln f Said members the edges of said flangesare faceted at about a 67.5

2. A structural block according to claim 1, comprisangle. ing six firstmembers and 12 second members, wherein

1. A polyhedral structural block suitable for use in constructingunderwater foundations, having a hollow core and perforated surfaces,comprising in combination: a. a plurality of flat rectangular firstmembers; b. a plurality of flat reCtangular second members having a pairof flanges extending outwardly at an obtuse angle from a pair ofparallel edges thereof, said plurality being twice the number of flatrectangular first members; c. a first generally annular ring formed froma plurality of alternating first and second rectangular members, thesurfaces of each member being at an acute angle to the surfaces ofabutting members and the flanges of said second members extendingradially and outwardly along the outer perimeter of said ring; d. asecond generally annular ring disposed at right angles to said firstring and having an imaginary axis which intersects an imaginary axis ofthe first ring at a point inside said hollow core, said second ringbeing formed from a plurality of alternating first and second membersand having a pair of opposed first members in common with said firstring, the flanges of the second members thereof extending radially andoutwardly along the perimeter of the second ring and each flangeabutting an adjacent flange on the first ring to form an acute angletherewith; e. a third generally annular ring disposed at right angles toboth said first and second rings and having an imaginary axis whichintersects the intersecting axes of said first and second rings, saidthird ring being formed from a plurality of alternating first and secondmembers and having one pair of opposed first members in common with saidfirst ring and a second pair of opposed first members in common withsaid second ring, the flanges of the second members thereof extendingradially and outwardly along the perimeter of the third ring andabutting adjacent flanges on the first and second rings to form acuteangles thereto, whereby a protruberant triangular opening is defined byabutting flanges of the three rings protruding outwardly from saidmembers.
 2. A structural block according to claim 1, comprising sixfirst members and 12 second members, wherein each generally annular ringis formed of eight of said members.
 3. A structural block according toclaim 2, wherein the edges of said first members are bevelled at about a67.5* angle.
 4. A structural block according to claim 3, wherein theflanges on said second members extend at an obtuse angle of about 126*.5. A structural block according to claim 4, wherein the edges of saidflanges are faceted at about a 67.5* angle.